http://www.ecs.com.tw/ECSWebSite/Product/Product_Model.aspx?CategoryID=1&TypeID=99&MenuID=115&childid=M_7&LanID=9#AMD
What more information can you provide about the motherboard, the ID number shows the chipset as being SiS761GX which is the onboard video
What other numbers are there on the motherboard that might identify it like "ECS 462ddxyz", for example
I've actually got the same problem with a Sony Vaio notebook, the only soundmax driver (version 4) that is available is from a site in Poland, written in Polish!
Okay, I've found a site that has your driver, it's 17.45mb -
http://www.driversdown.com/drivers/14372.shtml
edit - the audio is sometimes combined with the video chipset driver so you'd need to download the file and install it.